If this is true, the Song must be capable submarine with a capable crew. And the Americans who detected them were just as capable. Anyway i am sure this type of thing happens often. And to the military person... its not that suprising. Only suprising to some politician and people who want to make a big deal about it.
From memory, the Song carries anti ship missles with a range of more than 100km. If this true do u think the captain of the Song will risk getting so close to the CVBG in real combat. What do u think?